About this replacement
Google Pixel 3 — 3.85V Li-Polymer Replacement Battery (G013A-B)
This is a 3.85V, 2900mAh Li-Polymer battery for the Google Pixel 3 smartphone. It replaces OEM part G013A-B and fits the G013A and G013B hardware variants. Swap it in when the original cell has degraded, swells, or no longer holds a usable charge.
- Pixel 3 variant fit (G013A / G013B): Both G013A and G013B share the same battery bay dimensions, connector pinout, and BMS handshake — this cell covers both. The 71.80 × 51.60 × 5.00mm footprint matches the factory cavity with no modification needed.
- Bench tested on actual hardware: We ran this cell on a Pixel 3 unit and confirmed the BMS completed charge negotiation with the PMIC, fuel gauge IC initialised, and the charge cycle completed without cutoff errors.
- First-cycle calibration on the Pixel 3: After installation, disable fast charging for one full discharge-charge cycle. The Pixel 3 fuel gauge IC recalibrates its coulomb counter against the new cell's discharge curve on that first pass — fast charging before calibration pushes current into an uncalibrated cell and skews percentage readings.
Why the Pixel 3 reports wrong battery percentage after a cell swap
The Pixel 3 uses a fuel gauge IC that tracks capacity through a coulomb counter tuned to the original cell's impedance curve. A new cell has different internal resistance, so the counter starts with a mismatch. Until one full discharge-charge cycle completes, the reported percentage will drift — often showing 100% too quickly or dropping suddenly below 30%. One full uninterrupted cycle corrects the mapping.
Sudden shutdown at 20–25% on the new cell
This is a voltage cliff issue, not a capacity problem. Under high-current loads — active LTE modem, screen at full brightness, GPS — the new cell's voltage drops faster than the uncalibrated fuel gauge anticipates. The PMIC sees the rail fall below its cutoff threshold and shuts the device down even though the reported percentage looks safe. After one full calibration cycle the fuel gauge maps the actual voltage-to-capacity curve of this cell, and the shutdowns stop. If they persist past two cycles, check that the battery connector is fully seated — partial contact raises apparent impedance at the PMIC.